4. You notice some signs of nesting
You should check wall cavities, loft insulation, behind appliances, and garage corners since they like to get installed in their new home in darker spaces with less traffic in the house.
You can eventually notice them by their strong odors. In general, mice like to shred a lot of paper to get cozy.
Ladybugs are all adorable, but they are also predators. If you start noticing a couple of them in your house then you may have mites, whiteflies, or scale insects. It doesn’t count if you find them outdoors.